From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932114AbXDWDJH (ORCPT ); Sun, 22 Apr 2007 23:09:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932526AbXDWDJH (ORCPT ); Sun, 22 Apr 2007 23:09:07 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:50314 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932114AbXDWDJG (ORCPT ); Sun, 22 Apr 2007 23:09:06 -0400 Date: Mon, 23 Apr 2007 05:08:00 +0200 From: Ingo Molnar To: Gene Heskett Cc: Nick Piggin , linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Con Kolivas , Mike Galbraith , Arjan van de Ven , Peter Williams , Thomas Gleixner , caglar@pardus.org.tr, Willy Tarreau , Mark Lord , Ulrich Drepper Subject: Re: [patch] CFS scheduler, -v5 Message-ID: <20070423030800.GC10407@elte.hu> References: <20070420140457.GA14017@elte.hu> <20070423011229.GA20367@elte.hu> <20070423012509.GA25162@wotan.suse.de> <200704222239.40818.gene.heskett@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200704222239.40818.gene.heskett@gmail.com> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Gene Heskett wrote: > I haven't approached that yet, but I just noticed, having been booted > to this for all of 5 minutes, that although I told it not to renice x > when my script ran 'make oldconfig', and I answered n, but there it > is, sitting at -19 according to htop. > > The .config says otherwise: > [root@coyote linux-2.6.21-rc7-CFS-v5]# grep RENICE .config > # CONFIG_RENICE_X is not set > > So v5 reniced X in spite of the 'no' setting. Hmm, apparently your X uses ioperm() while mine uses iopl(), and i only turned off the renicing for iopl. (I fixed this in my tree and it will show up in -v6.) > Although I hadn't noticed it, one way or the other, I just set it (X) > back to the default -1 so that I'm comparing the same apples when I do > compare. note that CFS handles negative nice levels differently from other schedulers, so the disadvantages of agressively reniced X (lost throughput due to overscheduling, worse interactivity) do _not_ apply to CFS. I think the 'fair' setting would be whatever the scheduler writer recommends: for SD, X probably performs better at around nice 0 (i'll let Con correct me if his experience is different). On CFS, nice -10 is perfectly fine too, and you'll have a zippier desktop under higher loads. (on servers this might be unnecessary/disadvantegous so there this can be turned off.) (also, in my tree i've changed the default from -19 to -10 to make it less scary to people and to leave more levels to the sysadmin, this change too will show up in -v6.) Ingo